1. Field of the Invention
The present invention relates to a deaeration device for removing dissolved air in cleaning liquid and an ultrasonic cleaning device using this deaeration device.
2. Description of a Related Art
For an industrial cleaning device, it is crucial to completely remove stains or burrs adhered to parts and members for finishing. An ultrasonic cleaning device has been used as a cleaning device to do so.
The ultrasonic cleaning device separates and removes stains or burrs adhered to the surface of an object to be cleaned by vibration energy of an ultrasonic wave. An ultrasonic wave generator is mounted in a cleaning tank filled with cleaning liquid and the ultrasonic wave is irradiated toward the object to be cleaned which is immersed in the cleaning liquid.
With this type of ultrasonic cleaning device, it is known that sound pressure of the ultrasonic wave, that is, vibration energy of the ultrasonic wave, is greatly affected by concentration of dissolved air contained in the cleaning liquid. Dissolved air in large quantity prevents propagation of the ultrasonic wave, which causes energy loss and lowers sound pressure and cleaning capability. Accordingly, a deaeration device is attached to the ultrasonic cleaning device so as to reduce the dissolved air concentration in the cleaning liquid for efficient and stable cleaning.
An example of the above deaeration device is described in the Patent Document 1. The deaeration device in this Patent Document 1 is an example of a film-type deaeration device using a deaeration film which passes only air. A deaeration chamber, which is a sealed space, is divided by a deaeration film into two chambers, one of which is for flowing a liquid to be deaerated, while the other of which is connected to a vacuum pump and vacuumed by a negative pressure so that the dissolved air in the liquid is suctioned and removed through the deaeration film.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-249215 (all the pages, all the drawings).